The objectives of this project are: (1) to analyze data on the location of board-certified specialists by town size in 25 rural states from 1960 to 1977, (2) to explore factors that are associated with the presence of a specialist in a town, and (3) to estimate the effects of changes in the location of specialists on the distance the rural population must travel to receive specialty care. Computerized data bases will contain: (a) the name, population, latitude, longitude, number and type of board-certified specialists (internist, surgeon, pediatrician, obstetrician/gynecologist, family practitioners, radiologist, dermatologist, urologist, neurosurgeon) for every city or twon in 1960, 1970, and 1977; (b) the size and distribution of cities and towns larger than 2,500 population in each state, and (c) the location of the urban population (cities over 25,000) by combinations of census tracts and the less densely populated areas in 5x5 mile grids. Tabular presentations and plots will show the location of each type of specialist in each area for each of the three years. Logistic regression will be used to estimate the probabilty that a specialist will locate in a town as a function of its size and other attributes. A computer program calculates the distance of the non-urban population from the nearest specialist of each type. Plots will show the cumulative percent of each region or state population within x miles of each type of specialist. Results of this research should be useful in developing policy regarding the geographic and specialty distribution of physicians.